WS-AtomicTransaction defines a traditional ACID transactions model, based on two-phase commit (2PC). Many people believe that 2PC is not right for the loosely coupled nature of Web Services and they'd be right. However, this overlooks the other important aspect of Web Services: interoperability. Interoperability between existing vendor implementations is key for many transaction processing deployments, particularly those that have grown via acquisitions of heterogeneous technologies. This has been a transaction processing holy grail for many years.

WS-BusinessActivity provides a forward compensation model, much more appropriate for loosely coupled, long duration interactions. This latter model will probably have slower take-up than WS-AtomicTransaction, but it should become more important over time.

I definitely agree that this is a huge milestone. I recall Sven Frolund, Kannan Govindrajan, myself and others at HP labs discussing the compensation model back in the late '90's. Having participated with Mark and the others on this TC, I would like to state that the TC was conducted with the utmost formality and professionalism and for myself was certainly a learning experience in how such things should be handled.